It is an object of the present invention to provide a process and product whereby animal parts containing keratin, such as chicken, poultry, or other avian feathers, nails, beaks, and cattle or other animal horns, hooves and hair, are converted into KDMP complexes useful for topical application to human skin and nails to condition the same as hereinafter described.
Water soluble peptides present in fibrous keratin, on the average, contain fewer than ten amino acids, and under the conditions of the hydrolysis a number of the component amino acids are subject to chemical modification other than cleavage of peptide bonds. Amino acid analysis reveals an abundance of acidic and neutral amino acids as well as the presence of cystine and its oxidation products, most important of which is cysteine. An amber colored pigment exhibiting both cationic and hydrophobic properties is associated with the protein component.
Of the peptides obtained in the initial hydrolysate, in accordance with this invention, approximately 20% exhibit adsorption during a chromatography hydrophobic chromatographic support. During subsequent formulation steps an increasing number of the more polar peptides is lost, such that approximately 90% of the peptides present in the final formulation exhibit hydrophobic properties. Summarily, the protein component is composed of a family of structurally related low molecular weight peptides exhibiting both anionic and hydrophobic properties and containing the amino acid cystine.
The presence of naturally occurring cystine-cysteine has been found to be of particular importance in order to provide a product which is free from unpleasant odors. Where cysteine-cystine itself (unnatural) is added, it has been observed that there is a strong tendency for auto-oxidation and decomposition to occur and which produces a product having an unpleasant odor. Whereas, naturally derived or occurring cystine-cysteine obtained from KDMP, and produced as hereinafter described, is stable. The particular characteristic is explained by its reactivity, particularly its redox behavior (cysteine-cystine) which is of fundamental importance in cellular processes. The cystine in KDMP interacts with the abundant disulphide bridges present in keratin, found in the skin, hair and nails, thus markedly influencing the suppleness and elasticity of the skin treated. Apart from the direct improvement in the mechanical properties of the skin, the cystine also exhibits a stimulating effect on the metabolism of the epidermis.
It is known with respect to protein components of hair follicles, for example, that they are hydrophobic in nature and contain numerous sulfhydryl amino acid residues. Further, under the neutral or alkaline conditions, in accordance with this invention, cysteine reduction is accelerated in the presence of sulfhydryl containing compounds. Moreover, since the protein component of the present formulation, which contains a natural quantity of cystine, it serves as a thiol reducing reagent, thus increasing the cystine content of the hair. The peptides are absorbed by the hair, and it has been found that their affinity for a hydrophobic surface is favorably affected. These two independent phenomena acting in concert result in the formulation of a proteinaceous film which increases surface solubility, and protects the impact of environmental factors on the hair. The enhanced highlights observed with light reflecting hair colors also is attributed to the presence of a proteinaceous film which is a desirable attribute.
In addition, it has been observed that when utilizing the products of this invention, and wherein skin and nails are treated during the process with hot air flow drying, it results in the acceleration of cystine oxidation. Inasmuch as cystine associated with the protein component is absorbed by the hair, the oxidation results in the formation of cysteine molecular bridges between the hair follicle and proteinaceous film; thus stabilizing the film and producing a relatively hard and tough resistant surface on the skin or nail being treated.